In-situ synthesized nanostructured t-ZrO2/La2(Zr0.75Ce0.25)2O7 composite thermal barrier coatings

Abstract

As we all know, the poor toughness is an important factor that leads thermal barrier coatings to prematurely fail, which has been recognized as one of the urgent problems that need to be addressed. Herein, the nanostructured t-ZrO2/La2(Zr0.75Ce0.25)2O7 (LCZ) composite TBCs were constructed in-situ from plasma spraying. The microstructure and phase composition of nanostructured LCZ feedstocks and as-sprayed coatings were analysed. Moreover, the mechanism of in-situ synthesized nanostructured t-ZrO2/LCZ coatings was discussed in detail. Results show that as-sprayed coatings have the characteristics of bi-modal and dual-phase structures. The unmelted nanostructured LCZ feedstocks and in-situ synthesized ZrO2 nanoparticles are included in the nanostructured zone. The phase structure of coatings consists of fluorite LCZ and tetragonal ZrO2 (t-ZrO2). The presence of ZrO2 nanoparticles is derived from the decomposition of LCZ feedstocks during plasma spraying.